Cancer is the uncontrolled growth and spread of cells that may affect almost any tissue of the body. Lung, colorectal and stomach (gastric) cancer are among the five most common cancers in the world for both men and women. In the United States up to one third of the population develop cancer during their life span. As a result, in the USA alone it is estimated that about 500,000 individuals die from cancer annually (Ahmedin et al., CA Cancer J. Clin. 52:23-47 (2002)).
With global improvements in public health provision, populations are increasingly living to a greater age. The World Health Organisation estimates that more than 10 million people are diagnosed with cancer every year. It is further estimated that there will be 15 million new cases every year by 2020. In fact, cancer causes 6 million deaths every year-or 12% of deaths worldwide.
Turning to the biological perspective, as a normal cell progresses through the complex process of transformation to reach a cancerous, or ‘neoplastic’, state, its gene expression profile can typically change. Expression of certain genes that are usually dormant in a normal healthy cell may be turned on or up regulated in a cancer cell. Likewise, genes that maintain a normal healthy phenotype can be switched off or suppressed in cancer cells. Consequently, such genes can be viewed as biomarkers of neoplastic behavior in cells. In some circumstances the cell itself might not yet have even transformed into a cancerous cell, but may only be predisposed to such a change in future.
Previously, identification of cancers—for example gastric cancer—has relied upon traditional methods of diagnosis. For instance, detection of tumors in the stomach and esophagus is usually achieved by radiography, following ingestion of a ‘barium meal’. This results in potentially harmful exposure of the patient to X-rays. Hence, a less invasive method of tumor diagnosis, such as via blood or urine analysis is desirable.
Public awareness campaigns alerting individuals to the possible warning signs of cancer can have an impact on diagnosis and treatment of the disease. Large-scale cancer screening of otherwise healthy populations has also proven successful in some instances. Screening refers to the use of simple tests across a healthy population in order to identify individuals who have disease, but do not yet have symptoms. Examples include breast cancer screening using mammography and cervical cancer screening using cytology screening methods, including Pap smears. In order for screening to be successful it must be relatively simple to perform and consistently reliable.
However, there are currently very few large-scale screening programmes for cancers other than breast and cervical cancers. As a result, in many cases the disease can remain symptomatically undetectable in the patient until a very advanced stage. Hence, there is a need to identify novel markers of the presence of cancer and also the progression of the disease once it has become established in a patient. In particular, there is a need to identify novel genetic markers of the cancer that can be suitable candidates for inclusion in large scale screening programmes. In addition, there is a need to identify genes that are involved in the development and progression of cancer so that therapies can be designed accordingly.
The present invention relates to the identification of a novel marker for cancer called MH15. Expression of the MH15 gene is detectable in the blood of patients and the level of expression of the gene is correlated to the presence of cancer, particularly gastric cancer; breast cancer; pancreatic cancer; prostate cancer; uterine cancer; ovarian cancer; colon cancer; esophagus cancer; testicular cancer and lung cancer. The invention also provides methods and compositions for treating cancer, particularly gastric cancer; breast cancer; pancreatic cancer; prostate cancer; uterine cancer; ovarian cancer; colon cancer; esophagus cancer; testicular cancer and lung cancer.
These and other uses, features and advantages of the invention should be apparent to those skilled in the art from the teachings provided herein.